Walter, I am not writing this to irritate you or anyone else, this is purely informational for those who may not know. The idea of "views" is already built into the VHDL-AMS language. The language is structured so that there is an "entity" and inside the entity you can have multiple "architectures". The entity describes the equivalent of a SPICE subcircuit definition, the ports (nodes) and the generics (parameters) which may be the same for each architecture (view). The architecture contains the guts of the subcircuit, and since we can have multiple architectures, we can describe multiple views of the same thing. For example, an entity for a T-line could have multiple architectures: Ideal, RLGC, S-parameter, Pole/Zero, ImpulseResponse, YouNameIt Once there is a T-line entity in a library, all you need to do is add more architectures as your knowledge increases... In summary, VHDL-AMS already provides a netlisting syntax (which I believe is easily translated to any SPICE netlist) and it provides the multiple view syntax (entity/architecture). This is another point why I feel that there is no need for us to reinvent the wheel when it comes to designing our new EMD specification. It is already there, and I think this is actually pretty well done in VHDL-AMS... Arpad ============================================================ ________________________________ From: ibis-macro-bounce@xxxxxxxxxxxxx [mailto:ibis-macro-bounce@xxxxxxxxxxxxx] On Behalf Of Walter Katz Sent: Monday, June 30, 2008 10:29 AM To: scott@xxxxxxxxxxxxx Cc: IBIS Macro Subject: [ibis-macro] Re: EMD Pole-Zero Models (Why voltage controled sources?) Scott, My EMD proposal includes a concept of "Views". One view might be as simple as a lumped RLC, other views would include distributed RLGC (lossy and lossless), as well as S-parameter and Pole-Zero. Each view would contain information about the nature of the model and its bandwidth. I would not exclude the ability to include proprietary models as well, as long as comparably accurate non-proprietary models were included as well. Walter -----Original Message----- From: ibis-macro-bounce@xxxxxxxxxxxxx [mailto:ibis-macro-bounce@xxxxxxxxxxxxx]On Behalf Of Scott McMorrow Sent: Monday, June 30, 2008 11:08 AM To: kumarchi@xxxxxxxxx Cc: bob@xxxxxxxxxxxxx; wkatz@xxxxxxxxxx; IBIS Macro Subject: [ibis-macro] Re: [!! SPAM] Re: EMD Pole-Zero Models (Why voltage controled sources?) What IBIS would provide is the encapsulation and mapping to device/board/connector/cable pins in an EDA environment. For example, several connector companies provide models of their connectors in the following form: uncoupled spice lossless coupled spice S-parameter Pole-zero All of these could be provided as options in an EMD model, with the correct pin mapping. There is currently no IBIS model type available for boards with components, coupled and lossy interconnect. There is currently no IBIS model type available that can describe an actively equalized cable assembly. Scott McMorrow Teraspeed Consulting Group LLC 121 North River Drive Narragansett, RI 02882 (401) 284-1827 Business (401) 284-1840 Fax http://www.teraspeed.com Teraspeed® is the registered service mark of Teraspeed Consulting Group LLC C. Kumar wrote: before you go on to pole/zero approximation you should have an 'S' elements which directly provides the original s-parameter data either in time domain or freq domain. all the others like pole/zero are approximations, except in the case of circuit elements with analytic forms. You can add to your list controlled sources with data provided multi dimensional tables; controlled elements with hysterisis; a generic expression controlled source of the form f(v,i, parameters)=0 and so on and so forth. It is possible to reduce the controlled sources to a finite set (order of 10;s) however I am still with Arpad on this one here, unless I am not seeing something fundamental . These elements have been already implemented in equivalent forms in various flavors of spice and yes AMS and -A flavors. I fail to see how IBIS 'inventing' its own form and convince vendors and users to adopt the yet another new/even improved form. --- On Mon, 6/30/08, Walter Katz <wkatz@xxxxxxxxxx> <mailto:wkatz@xxxxxxxxxx> wrote: From: Walter Katz <wkatz@xxxxxxxxxx> <mailto:wkatz@xxxxxxxxxx> Subject: [ibis-macro] Re: EMD Pole-Zero Models (Why voltage controled sources?) To: bob@xxxxxxxxxxxxx Cc: "IBIS Macro" <ibis-macro@xxxxxxxxxxxxx> <mailto:ibis-macro@xxxxxxxxxxxxx> Date: Monday, June 30, 2008, 12:54 AM Bob, Thanks for digging this up on the use of controlled voltage source for the Laplace and Pole-Zero form of transfer functions. Is the following a correct summary: * A Touchstone file is a matrix of "Transfer Functions", where the "Transfer Function" is represented as a "Vector" of complex coefficients. o Each element of the "Vector" is the amplitude of the "Transfer Function" at a specific frequency. * Each of the "Transfer Functions" can be translated to Laplace form with a numerator and denominator polynomial. o Hspice implements the Laplace form using the E and G LAPLACE controlled voltage source. * The numerator and denominator Laplace polynomials can be factored, the numerator polynomial factored into a list of zeros, and the denominator factored into a list of poles. o Hspice implements the Pole-Zero form using the E and G POLE controlled voltage source. * Alternatively, each of "Transfer Functions" can be translated into "Impulse Responses" If this is correct, then Lossy RLGC, Touchstone, Laplace, Pole-Zero interconnect blocks can simply be represented as an EMD "Block" of the form: EMD_Block_xxxx <list of nodes> len=<length> type=<type> file=<file> * Where o EMD_Block_xxxx * Instance Designator o <list of nodes> * List of nodes o <length> * Length of interconnect in meters (applies only to RLGC) o <type> * RLGC * Touchstone * Laplace * Pole * Impulse o <file> * RLGC * Contains RLGC table data * Touchstone * sNp * Laplace * Contains Laplace polynomial coefficients * Format needs specification * Pole * Contains Pole Zero data * Format needs specification * Impulse * Contains Impulse Response data * Format needs specification It is a trivial exercise to convert any one of these "Types" of EMD_Blocks to Hspice W, S, E and G elements. If all of the above is correct, then there is no need for EMD_Blocks that are specifically voltage controlled sources. To answer your question: An EMD models for a group of interconnect pins is essentially an ICM [Nodal Path Description] where each of the N_sections is essentially an EMD_Block. The [Nodal Path Description] becomes a subckt with nodes consisting of external EMD pins and IBIS component pins. In ICM all of the N_section can either be all RLGC or all Touchstone. In EMD the EMD_Blocks can be any combination of RLGC, Touchstone, Laplace, Pole, Impulse, Resistor, Capacitor, Inductor, Conductance or K (coupling) elements. Walter -----Original Message----- From: ibis-macro-bounce@xxxxxxxxxxxxx [mailto:ibis-macro-bounce@xxxxxxxxxxxxx]On Behalf Of Bob Ross Sent: Sunday, June 29, 2008 10:53 PM To: wkatz@xxxxxxxxxx Cc: IBIS Macro Subject: [ibis-macro] Re: EMD Pole-Zero Models (Why voltage controled sources?) Walter: Here are some responses to your questions 1. HSPICE and some other SPICEs implement the Laplace and pole-zero elements as a network function WITHIN controlled sources including the VCVS (E) and VCCS (G) elements. The documention is hard to find, but the HSPICE syntax is in the HSPICE Applications Manual: Exxx n+ n- LAPLACE in+ in- k0 k1 ... kn / b0 b1 ... bm Gxxx n+ n- LAPLACE in+ in- k0 k1 ... kn / b0 b1 ... bm Exxx n+ n- POLE in+ in- a {cmpl zeros) / b (cmpl poles} Gxxx n+ n- POLE in+ in- a {cmpl zeros) / b (cmpl poles} 2. I think of a pole-zero block, not as the single Laplace transfer element, but as an n-port block such as proposed in some private Touchstone-like formats and possibly implemented internally and automatically from n-port table data. My question: When you say interconnect block modules of Resistor/Inductor/ Capacitor, do you really mean a low-level SPICE or SPICE-like syntax within "SPICE" subcircuits for interconnect structures? That is where K and controlled sources are valuable for many reasons. While we have not really discussed this, I have been assuming that we need such low-level capability for EMD. We could formally add a basic SPICE-syntax subcircuit to the list below as one of the modules with its internal SPICE-like netlist used for connecting the R/L/C/K/E/F/G/H ... elements. Bob Walter Katz wrote: > All, > > > > Based on the following assumptions for an EMD: > > > > * A module as a netlist of IBIS components and external pins > * Interconnect models between these IBIS component pins consist of a > netlist of interconnect blocks > * Interconnect block models are: > o Resistors > o Inductors > o Capacitors > o Distributed RLGC models > o S parameter Models > o Impulse Response Models > o Pole-Zero Models > > > > The purpose of this e-mail is to raise the issue of what is a Pole-Zero > model and why do we need voltage controlled sources. > > > > I refer to http://www.ece.uci.edu/docs/hspice/hspice_2001_2-217.html > > > > > Understanding Pole/Zero Analysis > > In pole/zero analysis, a network is described by its network transfer > function which, for any linear time-invariant network, can be written in > the general form: > > > > In the factorized form, the general function is: > > > > It seems to me that a Pole-Zero model can either be represented as a set > of numbers like the polynomial coefficients a0, b0, a1, b1, a2, b2, .. > or the factorized form a0, b0, z1, p1, z2, p2, ? > > Where is the controlled voltage source? > > I assume that one can model the pole-zero form into Spice, Verilog, and > VHDL primitives, and doing so might utilize controlled voltage sources > and other simulator specific models. > > Why it is not sufficient to just have a Pole-Zero model (either with > polynomial coefficients and/or pole-zero coefficients). > > Walter > -- Bob Ross Teraspeed Consulting Group LLC Teraspeed Labs 121 North River Drive 13610 SW Harness Lane Narragansett, RI 02882 Beaverton, OR 97008 401-284-1827 503-430-1065 http://www.teraspeed.com 503-246-8048 Direct bob@xxxxxxxxxxxxx Teraspeed is a registered service mark of Teraspeed Consulting Group LLC --------------------------------------------------------------------- IBIS Macro website : http://www.eda.org/pub/ibis/macromodel_wip/ IBIS Macro reflector: //www.freelists.org/list/ibis-macro To unsubscribe send an email: To: ibis-macro-request@xxxxxxxxxxxxx Subject: unsubscribe --------------------------------------------------------------------- IBIS Macro website : http://www.eda.org/pub/ibis/macromodel_wip/ IBIS Macro reflector: //www.freelists.org/list/ibis-macro To unsubscribe send an email: To: ibis-macro-request@xxxxxxxxxxxxx Subject: unsubscribe